}
}
+/**
+ * Share ephemeral public key
+ *
+ * @v tls TLS connection
+ * @v public Public key to fill in
+ * @ret rc Return status code
+ */
+static int tls_share_ephemeral ( struct tls_connection *tls, void *public ) {
+ struct tls_key_schedule *key = &tls->key;
+ struct tls_named_group *group = key->group;
+ struct exchange_algorithm *exchange = group->exchange;
+ size_t privsize = exchange->privsize;
+ struct {
+ uint8_t private[privsize];
+ } tmp;
+ int rc;
+
+ /* (Re)generate ephemeral private key */
+ tls_ephemeral_label ( tls, exchange->name, tmp.private, privsize );
+
+ /* Derive public key */
+ if ( ( rc = exchange_share ( exchange, tmp.private, public ) ) != 0 ) {
+ DBGC ( tls, "TLS %p could not share ephemeral key: %s\n",
+ tls, strerror ( rc ) );
+ goto err_share;
+ }
+
+ err_share:
+ memset ( &tmp, 0, sizeof ( tmp ) );
+ return rc;
+}
+
+/**
+ * Agree ephemeral public key (i.e. pre-master secret)
+ *
+ * @v tls TLS connection
+ * @v partner Partner public key
+ * @v partner_len Length of partner public key
+ * @v strip Strip/pad leading zeros
+ * @ret rc Return status code
+ */
+static int tls_agree_ephemeral ( struct tls_connection *tls,
+ const void *partner, size_t partner_len,
+ int strip ) {
+ struct tls_key_schedule *key = &tls->key;
+ struct tls_named_group *group = key->group;
+ struct exchange_algorithm *exchange = group->exchange;
+ size_t privsize = exchange->privsize;
+ size_t pubsize = exchange->pubsize;
+ size_t sharedsize = exchange->sharedsize;
+ struct {
+ uint8_t private[privsize];
+ uint8_t partner[pubsize];
+ uint8_t shared[sharedsize];
+ } *tmp;
+ size_t pad_len;
+ size_t shared_len;
+ uint8_t *shared;
+ int rc;
+
+ /* Allocate working space */
+ tmp = zalloc ( sizeof ( *tmp ) );
+ if ( ! tmp ) {
+ rc = -ENOMEM;
+ goto err_alloc;
+ }
+
+ /* (Re)generate ephemeral private key */
+ tls_ephemeral_label ( tls, exchange->name, tmp->private, privsize );
+
+ /* Zero-pad partner key if needed */
+ if ( partner_len > pubsize ) {
+ DBGC ( tls, "TLS %p partner key too long:\n", tls );
+ DBGC_HDA ( tls, 0, partner, partner_len );
+ rc = -EINVAL_KEY_EXCHANGE;
+ goto err_partner_len;
+ }
+ pad_len = ( pubsize - partner_len );
+ if ( pad_len && ( ! strip ) ) {
+ DBGC ( tls, "TLS %p partner key too short:\n", tls );
+ DBGC_HDA ( tls, 0, partner, partner_len );
+ rc = -EINVAL_KEY_EXCHANGE;
+ goto err_partner_len;
+ }
+ memcpy ( ( tmp->partner + pad_len ), partner, partner_len );
+
+ /* Agree shared secret */
+ if ( ( rc = exchange_agree ( exchange, tmp->private, tmp->partner,
+ tmp->shared ) ) != 0 ) {
+ DBGC ( tls, "TLS %p could not agree shared key: %s\n",
+ tls, strerror ( rc ) );
+ goto err_agree;
+ }
+
+ /* Strip leading zeros if needed */
+ shared = tmp->shared;
+ shared_len = sharedsize;
+ while ( strip && shared_len && ( ! *shared ) ) {
+ shared++;
+ shared_len--;
+ }
+
+ /* Set key derivation function secret to the shared secret */
+ DBGC ( tls, "TLS %p pre-master secret:\n", tls );
+ DBGC_HDA ( tls, 0, shared, shared_len );
+ tls_set_kdf_master ( tls, shared, shared_len );
+
+ err_agree:
+ err_partner_len:
+ memset ( tmp, 0, sizeof ( *tmp ) );
+ free ( tmp );
+ err_alloc:
+ return rc;
+}
+
/**
* Generate master secret
*
* @v tls TLS connection
- * @v pre_master_secret Pre-master secret
- * @v pre_master_secret_len Length of pre-master secret
*
* The client and server random values must already be known.
*/
-static void tls_generate_master_secret ( struct tls_connection *tls,
- const void *pre_master_secret,
- size_t pre_master_secret_len ) {
+static void tls_generate_master_secret ( struct tls_connection *tls ) {
struct digest_algorithm *digest = tls->key.digest;
uint8_t digest_out[ digest->digestsize ];
uint8_t master_secret[48];
tls_verify_handshake ( tls, digest_out );
/* Show inputs */
- DBGC ( tls, "TLS %p pre-master secret:\n", tls );
- DBGC_HD ( tls, pre_master_secret, pre_master_secret_len );
DBGC ( tls, "TLS %p client random bytes:\n", tls );
DBGC_HD ( tls, &tls->client.random, sizeof ( tls->client.random ) );
DBGC ( tls, "TLS %p server random bytes:\n", tls );
DBGC ( tls, "TLS %p session hash:\n", tls );
DBGC_HD ( tls, digest_out, sizeof ( digest_out ) );
- /* Set key derivation function secret to the pre-master secret */
- tls_set_kdf_master ( tls, pre_master_secret, pre_master_secret_len );
-
/* Generate master secret */
if ( tls->extended_master_secret ) {
tls_prf_label ( tls, master_secret, sizeof ( master_secret ),
tls_ephemeral_label ( tls, "classic pre-master",
&pre_master_secret.random,
sizeof ( pre_master_secret.random ) );
+ tls_set_kdf_master ( tls, &pre_master_secret,
+ sizeof ( pre_master_secret ) );
/* Encrypt pre-master secret using server's public key */
if ( ( rc = pubkey_encrypt ( pubkey, &tls->server.key, &cursor,
}
/* Generate master secret */
- tls_generate_master_secret ( tls, &pre_master_secret,
- sizeof ( pre_master_secret ) );
+ tls_generate_master_secret ( tls );
err_encrypt:
err_prepend:
size_t remaining;
size_t frag_len;
size_t param_len;
- size_t dh_ys_len;
- size_t privsize;
- size_t pubsize;
- size_t sharedsize;
unsigned int i;
int rc;
rc = -ENOTSUP_GROUP;
goto err_group;
}
+ tls->key.group = group;
exchange = group->exchange;
- privsize = exchange->privsize;
- pubsize = exchange->pubsize;
- sharedsize = exchange->sharedsize;
DBGC ( tls, "TLS %p using named group %s\n", tls, exchange->name );
- /* Check key length (allowing for missing leading zeros) */
- dh_ys_len = ntohs ( dh_ys->len );
- if ( dh_ys_len > pubsize ) {
- DBGC ( tls, "TLS %p invalid %s key\n", tls, exchange->name );
- DBGC_HDA ( tls, 0, tls->server.exchange,
- tls->server.exchange_len );
- rc = -EINVAL_KEY_EXCHANGE;
- goto err_key_len;
+ /* Generate pre-master secret */
+ if ( ( rc = tls_agree_ephemeral ( tls, dh_ys->data,
+ ntohs ( dh_ys->len ), 1 ) ) != 0 ) {
+ goto err_agree;
}
- /* Construct pre-master secret and ClientKeyExchange record */
+ /* Construct and send ClientKeyExchange record */
{
- uint8_t private[privsize];
+ size_t pubsize = exchange->pubsize;
struct {
uint32_t type_length;
uint16_t dh_xs_len;
uint8_t dh_xs[pubsize];
} __attribute__ (( packed )) *key_xchg;
- struct {
- uint8_t pre_master_secret[sharedsize];
- typeof ( *key_xchg ) key_xchg;
- } *dynamic;
- uint8_t *pre_master_secret;
- size_t pre_master_secret_len;
/* Allocate space */
- dynamic = malloc ( sizeof ( *dynamic ) );
- if ( ! dynamic ) {
+ key_xchg = malloc ( sizeof ( *key_xchg ) );
+ if ( ! key_xchg ) {
rc = -ENOMEM;
goto err_alloc;
}
- pre_master_secret = dynamic->pre_master_secret;
- pre_master_secret_len = sizeof ( dynamic->pre_master_secret );
- key_xchg = &dynamic->key_xchg;
-
- /* Generate ephemeral private key */
- tls_ephemeral_label ( tls, exchange->name, private,
- sizeof ( private ) );
/* Generate Client Key Exchange record */
key_xchg->type_length =
htonl ( sizeof ( *key_xchg ) -
sizeof ( key_xchg->type_length ) ) );
key_xchg->dh_xs_len = htons ( sizeof ( key_xchg->dh_xs ) );
- if ( ( rc = exchange_share ( exchange, private,
- key_xchg->dh_xs ) ) != 0 ) {
+ if ( ( rc = tls_share_ephemeral ( tls,
+ key_xchg->dh_xs ) ) != 0 ) {
goto err_share;
}
goto err_send_handshake;
}
- /* Zero-pad partner key as needed */
- memset ( key_xchg->dh_xs, 0, sizeof ( key_xchg->dh_xs ) );
- assert ( dh_ys_len <= sizeof ( key_xchg->dh_xs ) );
- memcpy ( &key_xchg->dh_xs[ sizeof ( key_xchg->dh_xs ) -
- dh_ys_len ],
- dh_ys->data, dh_ys_len );
-
- /* Generate pre-master secret */
- if ( ( rc = exchange_agree ( exchange, private,
- key_xchg->dh_xs,
- pre_master_secret ) ) != 0 ) {
- DBGC ( tls, "TLS %p could not exchange keys: %s\n",
- tls, strerror ( rc ) );
- goto err_agree;
- }
-
- /* Strip leading zeroes from pre-master secret */
- while ( pre_master_secret_len && ( ! *pre_master_secret ) ) {
- pre_master_secret++;
- pre_master_secret_len--;
- }
-
/* Generate master secret */
- tls_generate_master_secret ( tls, pre_master_secret,
- pre_master_secret_len );
+ tls_generate_master_secret ( tls );
- err_agree:
err_send_handshake:
err_share:
- free ( dynamic );
+ free ( key_xchg );
}
err_alloc:
- err_key_len:
+ err_agree:
err_group:
err_verify:
err_header:
uint8_t public[0];
} __attribute__ (( packed )) *ecdh;
size_t param_len;
- size_t privsize;
- size_t pubsize;
- size_t sharedsize;
int rc;
/* Parse ServerKeyExchange record */
tls->server.exchange_len );
return -ENOTSUP_GROUP;
}
+ tls->key.group = group;
exchange = group->exchange;
- privsize = exchange->privsize;
- pubsize = exchange->pubsize;
- sharedsize = exchange->sharedsize;
DBGC ( tls, "TLS %p using named group %s\n", tls, exchange->name );
- /* Check key length */
- if ( ecdh->public_len != pubsize ) {
- DBGC ( tls, "TLS %p invalid %s key\n", tls, exchange->name );
- DBGC_HDA ( tls, 0, tls->server.exchange,
- tls->server.exchange_len );
- return -EINVAL_KEY_EXCHANGE;
+ /* Generate pre-master secret */
+ if ( ( rc = tls_agree_ephemeral ( tls, ecdh->public,
+ ecdh->public_len, 0 ) ) != 0 ) {
+ return rc;
}
- /* Construct pre-master secret and ClientKeyExchange record */
+ /* Construct and send ClientKeyExchange record */
{
- uint8_t private[privsize];
- uint8_t pre_master_secret[sharedsize];
+ size_t pubsize = exchange->pubsize;
struct {
uint32_t type_length;
uint8_t public_len;
uint8_t public[pubsize];
} __attribute__ (( packed )) key_xchg;
- /* Generate ephemeral private key */
- tls_ephemeral_label ( tls, exchange->name, private,
- sizeof ( private ) );
-
/* Generate Client Key Exchange record */
key_xchg.type_length =
( cpu_to_le32 ( TLS_CLIENT_KEY_EXCHANGE ) |
htonl ( sizeof ( key_xchg ) -
sizeof ( key_xchg.type_length ) ) );
key_xchg.public_len = sizeof ( key_xchg.public );
- if ( ( rc = exchange_share ( exchange, private,
- key_xchg.public ) ) != 0 ) {
+ if ( ( rc = tls_share_ephemeral ( tls,
+ key_xchg.public ) ) != 0 ) {
return rc;
}
return rc;
}
- /* Generate pre-master secret */
- if ( ( rc = exchange_agree ( exchange, private, ecdh->public,
- pre_master_secret ) ) != 0 ) {
- DBGC ( tls, "TLS %p could not exchange keys: %s\n",
- tls, strerror ( rc ) );
- return rc;
- }
-
/* Generate master secret */
- tls_generate_master_secret ( tls, pre_master_secret,
- sizeof ( pre_master_secret ) );
+ tls_generate_master_secret ( tls );
}
return 0;
projects / thirdparty / ipxe.git / commitdiff
